For anticancer therapy, a method using various anticancer agents has been developed, however a surgical operation method of removing cancer cells is still most frequently used method. When the surgical operation method is used, technique to minimize surgical extent during surgery is necessary for post-surgical health and wellbeing of patients. In particular, for breast cancer, a lesion excised during surgery should be smaller for Korean women than other countries whose breast size is small, in order to achieve a goal of breast preservation therapy. Surgical extent is determined as a lesion and boundary margin regions around the lesion. In the case where an operating surgeon does not precisely know extent and region of a lesion, a great size of boundary margin regions around the lesion should be required. The reason is that, when extension of surgery is blindly reduced, a tumor may remain in the incised side. However, in actual clinical surgery, there is little method to allow an operating surgeon to precisely identify the lesion in real time during surgery. Although a very precise diagnostic method has been developed, the diagnostic method may not be used during surgery. Thus, during actual surgery, tactile sensation and vision of an operating surgeon are mainly used. However, in such a case, it is rare to clearly distinguish the lesion. In particular, in the case where a lesion is small, it is more difficult to distinguish. In order to achieve a goal of microinvasive surgery and preservation surgery, a technique is necessary to inform an operating surgeon about a lesion in real time during surgery.
In a typical surgery to remove a tumor, in particular, breast cancer surgery, a microlesion site of a patient is identified before surgery by ultrasonic waves, mammography, or magnetic resonance imaging. Then, the identified site of a lesion is marked, and thereafter, tissue in the marked region is removed. As a method for marking the identified site of a lesion, following methods are used: a method of drawing a picture on a skin surface, a method of using a wire, and a method of injecting a black pigment such as charcoal. Although the method of drawing a picture on skin by using a pen to mark a site of a lesion can be easily used, the method has a drawback of low accuracy, because, due to a very flexible characteristic of breast tissue, a shape of breast is greatly changed during surgery from a shape at the point of diagnosis, and, in the case of a lesion at deep breast, a mark on a skin surface is insufficient. Also, a drawback of the method of inserting a wire into a breast lesion is lower accuracy than expected because essentially a wire should be vertically inserted into a skin surface, but the vertical insertion of the wire may affect an ultrasonic probe, so that the wire is inevitably inserted obliquely; and because a location of the wire may be moved according to movement of breast. In addition, another drawback of the method is that the inserted wire interferes with surgery; and a procedure to excise a site for inserting the wire should be additionally performed. Finally, the method of injecting a pigment such as charcoal is advantageous in that the injected pigment binds to a lesion so that a site of the lesion may be accurately labeled. However, in the case of a lesion in deep breast, there are drawbacks in that a black pigment may not be identified at the exterior, and a surgical region may be contaminated by the pigment. These drawbacks also become a limitation in a surgical operation to remove cancer tissue beside breast cancer.
Thus, through technique developed so far, it is difficult to precisely determine an extent of surgery for surgically removing a cancer lesion. Consequently, when a cancer lesion is surgically removed, an excised region needs to be larger than necessary, and also inspection of identifying whether the lesion is normally removed or not should be accompanied after surgery.
Therefore, the present inventors have completed the present invention by demonstrating that, when a cancer lesion is surgically removed, a labeling agent including macroaggregated albumin, to which a pigment for staining living tissues is bound, effectively adsorbs to the cancer lesion, so that a site of the lesion can be accurately labeled; and that the pigment can be traced in real time, so that a range of the lesion to be removed can be accurately identified.